Aircraft control method and apparatus and aircraft

ABSTRACT

This invention discloses an aircraft control method, apparatus and an aircraft. The invention relates to the field of aircraft control technologies. The method includes: obtaining ambient luminance data by a luminance sensing apparatus of an aircraft; determining whether the ambient luminance data satisfies a luminance value required for normal running of a vision system of the aircraft; and adjusting, when the ambient luminance data does not satisfy the luminance value required for normal running of the vision system of the aircraft, a working status of a light emitting apparatus on the aircraft to change light emitting luminance of the light emitting apparatus. The foregoing aircraft control method, apparatus and the aircraft can accurately learn a flight environment in which the aircraft is located, thereby effectively implementing vision positioning on the aircraft and more conveniently controlling the aircraft.

This application is a continuation-in-part of International ApplicationNo. PCT/CN2018/082676 filed on Apr. 11, 2018, which claims priority toChinese Application No. CN201710557726.9 filed on Jul. 10, 2017, both ofwhich are hereby incorporated by reference in their entirety.

BACKGROUND Technical Field

The present application relates to the field of aircraft controltechnologies and in particular, to an aircraft control method, apparatusand an aircraft.

Related Art

An aircraft is a controllable flight device that has driving force,carries out a plurality of types of tasks and can be repeatedly used.Flight of the aircraft is controlled by using a wireless remote controldevice and a control apparatus of the aircraft.

Currently, the aircraft obtains information indicating a flightenvironment in which the aircraft is located by using a vision auxiliaryapparatus (or referred to as a vision system) during a flight, therebyassisting the aircraft to implement flight operations such as precisehovering and intelligent landing and obstacle avoidance. For example,when automatically landing, the aircraft detects a ground feature byusing the vision auxiliary apparatus to implement intelligent landingand obstacle avoidance of the aircraft.

However, in a low-light environment such as nighttime, light is dim,luminance of detected image data is low, and vision positioning cannotbe effectively performed on the aircraft by using the vision auxiliaryapparatus. Therefore, a flight environment in which the aircraft islocated cannot be clearly learned, causing much inconvenience to controlover the aircraft. For example, when the aircraft automatically lands,because light is dim, the surrounding environment cannot be accuratelylearned during landing. Consequently, the aircraft is very likely toland at an uneven position, causing damage to the aircraft due to arollover.

SUMMARY

To resolve a technical problem that vision positioning cannot beeffectively performed on an aircraft when light is low, the presentinvention provides an aircraft control method, apparatus and anaircraft.

According to a first aspect, an embodiment of the present inventionprovides an aircraft control method, including:

obtaining, by a luminance sensing apparatus of an aircraft, ambientluminance data;

determining whether the ambient luminance data satisfies a luminancevalue required for normal running of a vision system of the aircraft;and

if not, adjusting a working status of a light emitting apparatus on theaircraft so that the vision system of the aircraft runs normally.

According to a second aspect, an embodiment of the present inventionprovides an aircraft control apparatus, including:

an ambient luminance data obtaining module, configured to obtain ambientluminance data by using a luminance sensing apparatus of an aircraft;

a luminance determining module, configured to determine whether theambient luminance data satisfies a luminance value required for normalrunning of a vision system of the aircraft; and

a working status adjustment module, configured to adjust, when theambient luminance data does not satisfy the luminance value required fornormal running of the vision system of the aircraft, a working status ofa light emitting apparatus on the aircraft for normal running of thevision system of the aircraft.

According to a third aspect, an embodiment of the present inventionprovides an aircraft, including:

at least one processor; and

a memory in communication connection with the at least one processor,where

the memory stores an instruction executable by the at least oneprocessor and the instruction is executed by the at least one processor,so that the at least one processor is enabled to perform the methodaccording to the first aspect.

According to a fourth aspect, an embodiment of the present inventionprovides a computer-readable storage medium, configured to store aprogram, the program, when being executed, enabling an aircraft toperform the method according to the first aspect.

Further, according to a fifth aspect, an embodiment of the inventionprovides an aircraft, including:

a main body;

an arm connected to the main body;

a propulsion assembly disposed on the arm, wherein the propulsionassembly comprises a motor and a propeller;

a vision system disposed on the main body, wherein the vision systemcomprises a camera and a processor;

a flight control system disposed in the main body; and

a light emitting apparatus disposed on the main body or on the arm;

where one of the flight control system and the processor of the visionsystem is configured to perform the method discussed above.

The technical solutions provided in the embodiments of the presentinvention may include the following beneficial effects:

During flight of the aircraft, the ambient luminance data is obtained byusing the luminance sensing apparatus of the aircraft, the ambientluminance data indicating ambient luminance of a flight environment inwhich the aircraft is located. When it is determined that the ambientluminance data does not satisfy the luminance value required for normalrunning of the vision system of the aircraft, the working status of thelight emitting apparatus on the aircraft is adjusted and the ambientluminance of the flight environment in which the aircraft is located isfurther adjusted, so that under the adjusted ambient luminance, theflight environment in which the aircraft is located can be clearlylearned by using the vision system. In this way, vision positioning iseffectively performed on the aircraft and the aircraft is moreconveniently controlled.

It should be understood that the foregoing general descriptions and thefollowing detailed descriptions are merely examples and cannot limit thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutea part of this specification, illustrate embodiments of the presentinvention and, together with the specification, serve to explain theprinciples of the present invention.

FIG. 1 is a flowchart of an aircraft control method according to anexemplary embodiment;

FIG. 2 is a flowchart of another aircraft control method according to anembodiment corresponding to FIG. 1;

FIG. 3 is a flowchart of a specific implementation of step S310 in theaircraft control method according to an embodiment corresponding to FIG.2;

FIG. 4 is a method flowchart of specific scenario application of anaircraft control method according to an exemplary embodiment;

FIG. 5 is a block diagram of an aircraft control apparatus according toan exemplary embodiment;

FIG. 6 is a block diagram of another aircraft control apparatusaccording to an embodiment corresponding to FIG. 5;

FIG. 7 is a block diagram of a low-altitude flight determining module310 in the aircraft control apparatus according to an embodimentcorresponding to FIG. 6; and

FIG. 8 is a structural block diagram of a terminal according to anexemplary embodiment.

FIG. 9 is a schematic view of an unmanned aerial vehicle to implementthe method described in any of FIGS. 1-4.

FIG. 10 is another schematic view of the unmanned aerial vehicle shownin FIG. 9.

DETAILED DESCRIPTION

Exemplary embodiments are described in detail herein and examples of theexemplary embodiments are shown in the accompanying drawings. Theimplementations described in the following exemplary embodiments do notrepresent all implementations consistent with the present invention. Onthe contrary, the implementations are merely examples of apparatuses andmethods that are described in detail in the appended claims and that areconsistent with some aspects of the present invention.

It should be noted that the term “A and/or B” in this application meansat least one of A and B. That is, the term “A and/or B” should beconstrued as “A”, or “B”, or “A and B”.

FIG. 1 is a flowchart of an aircraft control method according to anexemplary embodiment. As shown in FIG. 1, the method of controlling theaircraft may include the following steps.

In step S110, ambient luminance data is obtained by using a luminancesensing apparatus of an aircraft.

The aircraft is a controllable flight device that has driving force,carries out a plurality of types of tasks and can be repeatedly used.

The aircraft is provided with the luminance sensing apparatus thatassists the aircraft to learn a current flight environment, therebyimplementing flight control over the aircraft.

The luminance sensing apparatus is a device performing luminancedetection. The luminance sensing apparatus may be a camera or anotherdevice such as a light sensor.

The ambient luminance data may indicate ambient luminance of anenvironment in which the aircraft is located or ambient luminance of anenvironment in which a vision system on the aircraft is located.

When the aircraft is flying, ambient luminance detection is performed onthe flight environment by using the luminance sensing apparatus disposedon the aircraft.

In a specific exemplary embodiment, during a flight, the aircraftobtains image data of the flight environment by using a camera (forexample, a monocular camera, a binocular camera or a gimbal camera)disposed on the aircraft and further performs analysis processing on theimage data in the camera to obtain luminance data, so as to perceive theambient luminance of the flight environment in which the aircraft islocated.

For example, optical flow quality or an exposure amount of an image inthe camera is obtained and luminance of the image is further learnedbased on the optical flow quality or the exposure amount, so as todetermine the ambient luminance of the flight environment in which theaircraft is located.

In an embodiment, the luminance sensing apparatus may be the visionsystem on the aircraft. The vision system includes a camera and aprocessor connected to the camera. The camera of the vision systemincludes at least one of monocular camera, binocular camera, and gimbalcamera. The processor may determine optical flow quality and/or anexposure amount of an image based on the image taken by the camera. Theoptical flow quality is used for representing resolution of a texture inthe image. That is, higher optical flow quality indicates higherresolution of the texture in the image; and lower optical flow qualityindicates lower resolution of the texture in the image. It may also beunderstood as that higher optical flow quality of the image indicates amore precise distance value obtained by the vision system throughcalculation by using the image. If the optical flow quality of the imageis excessively low, the vision system cannot perform distancecalculation by using the image, that is, cannot run normally.

The exposure amount is used for representing an exposure degree of theimage. It may also be understood as that, if the exposure amount ishigh, it indicates that external light is sufficient. The aircraft islikely to be located in a high-light environment such as a daytimeoutdoor environment. If the exposure amount is low, it indicates thatthe aircraft is in a low-light environment such as a nighttime outdoorenvironment. In an embodiment, the exposure amount includes at least oneof an exposure time and an exposure gain. In some embodiments, one ofthe exposure time and the exposure gain is used as a parameter torepresent the ambient luminance data. In some other embodiments, boththe exposure time and the exposure gain are used as parameters torepresent the ambient luminance data.

The aircraft may obtain at least one of the optical flow quality and theexposure amount from the vision system, and determine, based on theambient luminance parameter, whether a luminance value required fornormal running of the vision system of the aircraft is satisfied.

In another embodiment, the luminance sensing apparatus may be anapparatus such as a light sensor. The aircraft may obtain light data orambient luminance data collected by the light sensor. The light data orthe ambient luminance data is used for indicating intensity of ambientlight. For example, a larger value of the light data or the ambientluminance data indicates stronger light of the environment in which theaircraft is located.

In step S120, it is determined whether the ambient luminance datasatisfies a luminance value required for normal running of a visionsystem of the aircraft; and if yes, no processing is performed; or ifnot (N), step S130 is performed.

The vision system is a collection of hardware and software used forimage collection and analysis processing in the aircraft.

When the vision system normally runs, it converts a photographed targetinto an image signal, then transforms information about pixeldistribution, luminance and a color in the image signal into digitizedsignals and performs various types of calculation on these digitizedsignals to extract features of the target, so as to obtain informationabout optical flow quality or an exposure amount.

However, when the ambient luminance data indicates that the ambientluminance of the flight environment in which the aircraft is located isexcessively low, the image signal obtained by the vision system haslittle relevance to the flight environment. Consequently, the flightenvironment in which the aircraft is located cannot be accuratelylearned.

When it is determined whether the ambient luminance data satisfies theluminance value required for normal running of the vision system of theaircraft, lowest flight luminance may be preset. When the ambientluminance indicated by the ambient luminance data is lower than thelowest flight luminance, it is considered that the ambient luminancedata does not satisfy the luminance value required for normal running ofthe vision system of the aircraft. Alternatively, when the vision systemcannot accurately identify scenery information from collected imageinformation, it is determined that the ambient luminance data does notsatisfy the luminance value required for normal running of the visionsystem of the aircraft. Whether the ambient luminance data satisfies theluminance value required for normal running of the vision system of theaircraft may alternatively be determined in another manner.

For example, lowest flight luminance is preset to be used as theluminance value required for normal running of the vision system of theaircraft. When the ambient luminance of the flight environment in whichthe aircraft is located is lower than the lowest flight luminance, thescenery information of the flight environment in which the aircraft islocated cannot be accurately learned by using the vision system of theaircraft. Consequently, vision positioning cannot be effectivelyperformed on the aircraft. Therefore, by presetting the lowest flightluminance, when the ambient luminance is lower than the lowest flightluminance, a working status of a light emitting apparatus disposed onthe aircraft is adjusted.

In another implementation, when the luminance sensing apparatus is thevision system, the aircraft can obtain the optical flow quality and theexposure amount output by the vision system and further determine, basedon the optical flow quality and the exposure amount, whether the ambientluminance data satisfies the luminance value required for normal runningof the vision system of the aircraft.

Specifically, the aircraft may first determine whether a value of theoptical flow quality is less than a preset optical flow qualitythreshold.

The optical flow quality threshold may be determined based on opticalflow quality of an image that can be processed by the vision system. Ifthe value of the optical flow quality is less than a value, the visionsystem cannot process the image. For example, the vision system cannotidentify a target object in the image or cannot calculate the distanceby using the image. That is, the vision system cannot run normally. Inthis way, the value may be determined as the preset optical flow qualitythreshold. If the value of the optical flow quality is less than theoptical flow quality threshold, it indicates that resolution of atexture of an image currently obtained by the vision system is low. Andthe step S130 may be then performed. However, it may be furtherdetermined whether the working status of the light emitting apparatus onthe aircraft needs to be adjusted.

Optionally, if the value of the optical flow quality is less than theoptical flow quality threshold, it may be further determined whether avalue of the exposure amount is less than a preset exposure threshold.In an embodiment, the exposure threshold is a value of an exposure timeor a value of an exposure gain. In another embodiment, the presetexposure threshold includes a value of an exposure time and a value ofan exposure gain.

If the value of the exposure amount is less than the exposure threshold,it indicates that the aircraft is in a low-light state currently and theambient luminance data does not satisfy the luminance value required fornormal running of the vision system. That is, the working status of thelight emitting apparatus on the aircraft needs to be adjusted and stepS130 is performed. However, it should be noted that the step ofcomparing the value of the optical flow quality with the optical flowquality threshold can be omitted.

If the value of the exposure amount is greater than or equal to theexposure threshold, it indicates that the aircraft is not in thelow-light state currently. That is, low optical flow quality is notcaused because the aircraft is in a low-light environment. Therefore,the vision system needs to be adjusted in another manner to improve theoptical flow quality obtained by the vision system.

It should be noted that, if the luminance sensing apparatus is thevision system, the aircraft determines, by using the ambient luminancedata fed back by the vision system, whether the ambient luminance datasatisfies the luminance value required for normal running of the visionsystem, that is, the luminance sensing apparatus. In such a manner,ambient luminance of an environment in which the vision system islocated may be learned more accurately.

In some embodiments, the luminance sensing apparatus may detect framerate of optical flow image. If the frame rate of the optical flow imageis less than a preset frame rate threshold, it is determined that theaircraft is in a low-light environment and that the ambient luminancedata fails to satisfy the luminance value required for normal running ofa vision system of the aircraft.

In an embodiment, the step S120 is performed by the processor of thevision system. In another embodiment, the step S120 is performed by aflight control system of the aircraft. The flight control system can beimplemented as one of an application specific integrated circuit (ASIC)and a field programmable gate array (FPGA). The flight control system isconfigured to control the flight of the aircraft.

In step S130, when the ambient luminance data does not satisfy theluminance value required for normal running of the vision system of theaircraft, a working status of a light emitting apparatus on the aircraftis adjusted so that the vision system of the aircraft runs normally.

In an embodiment, the step of adjusting is performed by the processor ofthe vision system. In another embodiment, the step of adjusting isperformed by the flight control system of the aircraft.

The light emitting apparatus is a device that is disposed on theaircraft and that can emit light.

The light emitting apparatus may be a signal indicator on the aircraftor a lighting device such as a light emitting diode (LED) lamp or anincandescent lamp disposed on the aircraft.

In an embodiment, the light emitting apparatus is disposed on an arm ofthe aircraft, where the arm is connected to a main body of the aircraft.A plurality of electrical components, including at least one of a flightcontrol system, the vision system, GPS module and battery, are disposedin or on the main body. In another embodiment, the light emittingapparatus is disposed on an upper member of the main body. In someembodiments, the light emitting apparatus is disposed on a bottom (lowermember) of the main body. Certainly, in an embodiment, the lightemitting apparatus may be disposed near the vision system. The visionsystem is connected to the main body and may be located at bottom of themain body. In other embodiment, the vision system may be located at afront side or a rear side of the main body. A position at which thelight emitting apparatus is disposed on the aircraft is not limited,provided that the light emitting apparatus can adjust, on the aircraft,the ambient luminance of the environment in which the vision system islocated.

When the ambient luminance data does not satisfy the luminance valuerequired for normal running of the vision system of the aircraft, theworking status of the light emitting apparatus on the aircraft needs tobe adjusted and the ambient luminance of the flight environment in whichthe aircraft is located is further adjusted based on the luminance valuerequired for normal running of the vision system of the aircraft, untilthe detected ambient luminance data satisfies the luminance valuerequired for normal running of the vision system of the aircraft.

Optionally, when the working status of the light emitting apparatus onthe aircraft is adjusted, a light emitting color of the light emittingapparatus may be changed, for example, from green to white, so as toincrease the light emitting luminance of the light emitting apparatus.Alternatively, luminance of the light emitting apparatus may be directlyadjusted. Alternatively, the luminance of the light emitting apparatusmay be adjusted by controlling on or off of the light emittingapparatus. For example, the light emitting apparatus is enabled when thelight emitting apparatus is disabled, so as to adjust the luminance ofthe light emitting apparatus. The working status of the light emittingapparatus on the aircraft may be further adjusted in another manner.

The ambient luminance of the flight environment in which the aircraft islocated changes by adjusting the working status of the light emittingapparatus. When the ambient luminance of the flight environment in whichthe aircraft is located is sufficient, the flight environment in whichthe aircraft is located can be clearly learned for convenience of flightcontrol over the aircraft.

For example, when it is learned by using the camera of the aircraft thatthe ambient luminance of the flight environment in which the aircraft islocated is low, luminance of a lighting lamp disposed on the aircraft isincreased, thereby increasing the ambient luminance of the flightenvironment in which the aircraft is located, so as to clearly learn thescenery information of the flight environment in which the aircraft islocated; when it is learned by using the luminance sensing apparatus ofthe aircraft that the ambient luminance of the flight environment inwhich the aircraft is located is high, the luminance of the lightinglamp disposed on the aircraft is decreased, thereby decreasing theambient luminance of the flight environment in which the aircraft islocated, so as to reduce power consumption when it is ensured that theflight environment in which the aircraft is located can be clearlylearned.

In an implementation, when the luminance sensing apparatus is the visionsystem, after it is determined that the ambient luminance data does notsatisfy the luminance value required for normal running of the visionsystem of the aircraft, the working status of the light emittingapparatus on the aircraft can be adjusted based on the optical flowquality and/or the exposure amount in the ambient luminance data.

For example, the light emitting luminance of the light emittingapparatus may be adjusted based on the optical flow quality. Forexample, a smaller value of the optical flow quality indicates a largerdegree to which the light emitting luminance is adjusted. That is, theoptical flow quality is negatively correlated to the light emittingluminance.

Alternatively, the light emitting luminance of the light emittingapparatus may be adjusted based on the exposure amount. For example, asmaller value of the exposure amount indicates a larger degree to whichthe light emitting luminance is adjusted. That is, the exposure amountis negatively correlated to the light emitting luminance.

Alternatively, the light emitting luminance of the light emittingapparatus may be adjusted with reference to both the optical flowquality and the exposure amount. The optical flow quality and theexposure amount obtained by the vision system may be improved byadjusting the light emitting luminance, to make the vision system runnormally.

Certainly, another working status of the light emitting apparatus may beadjusted based on the foregoing parameters. For example, the lightemitting color of the light emitting apparatus is adjusted or on or offof the light emitting apparatus is adjusted.

Optionally, a working status of a light emitting apparatus, on theaircraft, related to the vision system may be further adjusted.

That the light emitting apparatus is related to the vision system may bethat a position at which the light emitting apparatus is disposed on theaircraft is related to a position at which the vision system is disposedon the aircraft. That is, a light emitting apparatus that can affect theambient luminance of the vision system by adjusting the working statusis the light emitting apparatus related to the vision system.

For example, a light emitting apparatus is disposed on an arm of theaircraft and a vision system is located at a bottom portion of theaircraft, that is, a lower viewing vision system. The light emittingapparatus related to the lower viewing vision system may be a lightemitting apparatus disposed on each arm of the aircraft. A lightemitting apparatus related to a vision system located at a front end ofthe aircraft, that is, a front viewing vision system, may be a lightemitting apparatus on a front end arm of the aircraft. A light emittingapparatus related to a vision system located at a rear end of theaircraft, that is, a rear viewing vision system, may be a light emittingapparatus on a rear end arm of the aircraft.

Further, if there is a plurality of light emitting apparatuses relatedto the vision system, working statuses of some or all of the lightemitting apparatuses may be adjusted to adjust the ambient luminance ofthe environment in which the vision system is located. In an embodiment,the at least two light emitting apparatuses may be enabledsimultaneously.

Optionally, after the working status of the light emitting apparatus onthe aircraft is adjusted, the aircraft may further obtain new ambientluminance data and determine whether the new ambient luminance datasatisfies the luminance value required for normal running of the visionsystem of the aircraft. If not, the working status of the light emittingapparatus may be further adjusted until the new ambient luminance datasatisfies the luminance value required for normal running of the visionsystem of the aircraft.

Further, after the aircraft determines that the new ambient luminancedata satisfies the luminance value required for normal running of thevision system, the aircraft may further determine whether a value of thenew ambient luminance data is far greater than the luminance valuerequired for normal running of the vision system. If yes, the lightemitting luminance of the light emitting apparatus may be decreased toreduce power consumption of the aircraft when an ambient luminancerequirement of the vision system is met.

The ambient luminance of the flight environment in which the aircraft islocated is learned by using the luminance sensing apparatus of theaircraft by using the method described above. Further, when the ambientluminance data does not satisfy the luminance value required for normalrunning of the vision system of the aircraft, the working status of thelight emitting apparatus on the aircraft is adjusted to change the lightemitting luminance of the light emitting apparatus, so as to change theambient luminance of the flight environment in which the aircraft islocated. In this way, the flight environment in which the aircraft islocated is accurately learned, vision positioning on the aircraft iseffectively implemented and the aircraft is controlled moreconveniently.

FIG. 2 shows another aircraft control method according to an embodimentcorresponding to FIG. 1. As shown in FIG. 2, before step S120, theaircraft control method may further include the following steps.

In step S310, it is determined that an aircraft is in a low-altitudeflight state.

The step S310 can be performed by the processor of the vision system orthe flight control system of the aircraft.

It should be noted that the sequence to implement this step S310 is notlimited in the invention. The step S310 can be performed before the stepS110 or the step S120.

The low-altitude flight state means that the aircraft flies at a lowheight.

There is a plurality of manners to determine that the aircraft is in thelow-altitude flight state. For example, it is determined based on aflight height of the aircraft that the aircraft is in the low-altitudeflight state. For another example, a detection range of an ultrasonicwave is approximately 5 meters. When a reflected ultrasonic wave can bereceived after the ultrasonic wave is transmitted to the ground, it isdetermined that the aircraft is in the low-altitude flight state. Foranother example, a detection range of an infrared ray is approximately10 meters. When a reflected infrared ray can be received after theinfrared ray is transmitted to the ground, it is determined that theaircraft is in the low-altitude flight state. Herein, a manner ofdetermining that the aircraft is in the low-altitude flight state is notlimited.

In the low-altitude flight state, because the flight height is low, theaircraft is very likely to collide with a building on the ground.Therefore, a flight environment in which the aircraft is located isobtained by using a vision system, so that the aircraft can avoidobstacles during a flight.

However, at night, when the aircraft is in the low-altitude flightstate, luminance of an environment in which the aircraft is located islow, and thus the flight environment in which the aircraft is locatedcannot by accurately learned by using the vision system, leading to muchinconvenience to control over the aircraft. Therefore, light emittingluminance of a light emitting apparatus is changed by adjusting aworking status of the light emitting apparatus disposed on the aircraftand ambient luminance of the flight environment in which the aircraft islocated is increased, so as to accurately learn scenery information ofthe flight environment in which the aircraft is located, effectivelyimplement vision positioning on the aircraft and control the aircraftmore conveniently.

For example, at night, when the aircraft automatically lands, theaircraft is in the low-altitude flight state. The luminance of theenvironment in which the aircraft is located is perceived to be low byusing a camera of the aircraft. In this case, a lighting lamp disposedon an arm of the aircraft is enabled and luminance of the lighting lampis gradually increased to increase ambient luminance until the visionsystem can accurately process, under the ambient luminance, imageinformation of the flight environment in which the aircraft is located.In this way, the flight environment in which the aircraft is located canbe clearly learned and the aircraft automatically lands at a safeposition. Therefore, intelligent landing and obstacle avoidance of theaircraft is implemented, preventing the aircraft from landing at anuneven disadvantageous position and rolling over when the aircraftcannot accurately learn the flight environment in which the aircraft islocated, causing damage to the aircraft.

For another example, in a low-altitude flight at night, the aircraftperforms a hovering operation. The luminance of the environment in whichthe aircraft is located is perceived to be low by using the camera ofthe aircraft. In this case, the lighting lamp disposed on the arm of theaircraft is enabled and luminance of the lighting lamp is graduallyincreased to increase the ambient luminance until the vision system canaccurately process, under the ambient luminance, the image informationof the flight environment in which the aircraft is located. In this way,the flight environment in which the aircraft is located can be clearlylearned and the aircraft automatically hovers at a safe position.Therefore, precise hovering of the aircraft is implemented, preventingthe aircraft from colliding with an obstacle such as a low-altitudebuilding when the aircraft cannot accurately learn the flightenvironment in which the aircraft is located during hovering, causingcollision damage to the aircraft.

When the aircraft is not in the low-altitude flight state, no processingmay be performed, or the lighting lamp disposed on the aircraft may beturned off and no processing is performed on a signal indicator.

When it is determined that the aircraft is not in the low-altitudeflight state, the lighting lamp disposed on the aircraft is disabledregardless of whether the ambient luminance of the flight environment inwhich the aircraft is located is sufficient, so as to reduce powerconsumption of the aircraft.

When the aircraft is in a high-altitude flight state, even if under theambient luminance of the flight environment in which the aircraft islocated, the vision system cannot accurately process the imageinformation of the flight environment in which the aircraft is located.The aircraft can be easily controlled by using a barometer, a GPS or thelike. A possibility that an obstacle exists at a high altitude is low.Therefore, no impact is caused to a flight of the aircraft when thelighting lamp disposed on the aircraft is disabled.

The method described above is used to determine whether the aircraft isin the low-altitude flight state. When the aircraft is in thelow-altitude flight state, luminance adjustment is performed, based onthe ambient luminance, on the light emitting apparatus disposed on theaircraft, so that the ambient luminance meets a processing requirementof the vision system. Therefore, the flight environment in which theaircraft is located is accurately learned, vision positioning iseffectively implemented on the aircraft and the aircraft is controlledmore conveniently. When the aircraft is not in the low-altitude flightstate, the lighting lamp disposed on the aircraft is disabled to reducepower consumption.

In the foregoing case, the aircraft may perform luminance adjustment fora lower viewing vision system, or perform luminance adjustment based ona related scenario for another vision system such as a front viewingvision system or a rear viewing vision system.

FIG. 3 shows further detailed descriptions of step S310 in theembodiment corresponding to FIG. 2 according to an exemplary embodiment.As shown in FIG. 3, step S310 may include the following steps.

In step S311, a flight height of the aircraft is obtained.

The flight height is an altitude height or a height from the ground whenthe aircraft flies.

During a flight of the aircraft, the flight height of the aircraft isdetected by using a device such as an ultrasonic wave, a barometer or aninfrared detector.

In step S312, it is determined, by comparing the flight height with apreset low-altitude height threshold, that the aircraft is in thelow-altitude flight state when the flight height reaches thelow-altitude height threshold.

The low-altitude height threshold is a preset height critical value of alow-altitude state and a high-altitude state.

If the flight height is below the low-altitude height threshold, itindicates that the aircraft is in the low-altitude flight state; and ifthe flight height is above the low-altitude height threshold, itindicates that the aircraft is in a high-altitude flight state.

For example, the preset low-altitude height threshold is 10 meters. At amoment T1, an obtained flight height H1 of the aircraft is 10 meters,and then the aircraft is determined to be in the low-altitude flightstate. At a moment T2, an obtained flight height H2 of the aircraft is30 meters, and then the aircraft is determined to be in thehigh-altitude flight state.

In the method described above, it is determined, based on the flightheight of the aircraft and the preset low-altitude height threshold,that the aircraft is in the low-altitude flight state. In addition, theworking status of the light emitting apparatus disposed on the aircraftis adjusted based on ambient luminance of the aircraft, to change thelight emitting luminance of the light emitting apparatus, therebyadjusting the ambient luminance of the flight environment in which theaircraft is located. In this way, under the ambient luminance, theflight environment in which the aircraft is located can be accuratelylearned, vision positioning is effectively implemented on the aircraftand convenience is brought to control over the aircraft.

The foregoing method of controlling an aircraft is described in detailbelow with reference to a specific application scenario. The aircraftcontrol method is operated in an aircraft. Details are shown in FIG. 4.

Step S501: Obtain ambient luminance data, that is, obtain the ambientluminance data by using a luminance sensing apparatus of the aircraft.

Step S502: Determine luminance, that is, determine whether the ambientluminance data satisfies a luminance value required for normal runningof a vision system of the aircraft; and if yes (Y), perform noprocessing; or if not (N), perform step S503: Obtain a flight height,that is, obtain a flight height of the aircraft.

In an embodiment, the step S502 is performed by a processor of thevision system, or a flight control system, and the step S503 isperformed by a flight control system or a processor of the visionsystem.

In an embodiment, the step 503 is performed before the step S502.

After step S503 is performed, step S504 is subsequently performed:Determine a low altitude, that is, determine whether the aircraft is ina low-altitude flight state by comparing the flight height with a presetlow-altitude height threshold.

If the aircraft is in the low-altitude flight state (Y), step S505 isperformed: Adjust a working status, that is, adjust a working status ofa light emitting apparatus on the aircraft.

If the aircraft is not in the low-altitude flight state (N), step S506is performed: Disable a lighting lamp of the aircraft.

Preferably, the steps S503 and S504 are performed by a same unit of theaircraft, such as the flight control system or the processer of thevision system. The step S505 and S506 are performed by the flightcontrol system of the aircraft or the processor of the vision system ofthe aircraft.

The following is an apparatus embodiment of the present invention, whichcan be used to execute the embodiments of the foregoing aircraft controlmethod. For details not disclosed in the apparatus embodiment of thepresent invention, refer to the embodiments of the aircraft controlmethod of the present invention.

FIG. 5 is a block diagram of a control apparatus of an aircraftaccording to an exemplary embodiment. The apparatus includes but is notlimited to an ambient luminance data obtaining module 110, a luminancedetermining module 120 and a working status adjustment module 130.

The ambient luminance data obtaining module 110 is configured to obtainambient luminance data by using a luminance sensing apparatus of anaircraft, the ambient luminance data indicating ambient luminance of aflight environment in which the aircraft is located.

The luminance determining module 120 is configured to determine whetherthe ambient luminance data satisfies a luminance value required fornormal running of a vision system of the aircraft.

The working status adjustment module 130 is configured to adjust, whenthe ambient luminance data does not satisfy the luminance value requiredfor normal running of the vision system of the aircraft, a workingstatus of a light emitting apparatus on the aircraft.

For details of implementation processes of a function and an effect ofeach module in the apparatus, refer to implementation processes ofcorresponding steps in the foregoing aircraft control method, which isnot described herein again.

Optionally, as shown in FIG. 6, the aircraft control apparatus accordingto an embodiment corresponding to FIG. 5 further includes but is notlimited to a low-altitude flight determining module 310.

The low-altitude flight determining module 310 is configured todetermine that the aircraft is in a low-altitude flight state.

Optionally, as shown in FIG. 7, in an aircraft control apparatusaccording to an exemplary embodiment corresponding to FIG. 6, thelow-altitude flight determining module 310 includes but is not limitedto a flight height obtaining unit 311 and a height comparison unit 312.

The flight height obtaining unit 311 is configured to obtain a flightheight of the aircraft.

The height comparison unit 312 is configured to determine, by comparingthe flight height with a preset low-altitude height threshold, that theaircraft is in the low-altitude flight state when the flight heightreaches the low-altitude height threshold.

Optionally, in the aircraft control apparatus according to theembodiment corresponding to FIG. 6, the apparatus further includes butis not limited to a lighting lamp disabling module.

The lighting lamp disabling module is configured to disable a lightinglamp disposed on the aircraft when the aircraft is not in thelow-altitude flight state.

Optionally, in the aircraft control apparatus according to theembodiments corresponding to FIG. 5, FIG. 6 and FIG. 7, the workingstatus adjustment module 130 includes one or more of a light emittingcolor changing unit 131, a luminance adjustment unit 132 and a lightemitting apparatus on and off control unit 133.

The foregoing modules may be implemented by using software, hardware ora combination thereof configured in the aircraft. For example, aprocessor in the aircraft, for example, a processor in a flight controlsystem or a processor in a primary controller, implements functions ofthe foregoing modules by invoking a program stored in a memory.

FIG. 8 is a block diagram of a terminal 100 according to an exemplaryembodiment. The terminal 100 may be the aircraft described in theforegoing embodiments and is configured to perform all or some of thesteps in any of the methods shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4.

Referring to FIG. 8, the terminal 100 may include one or more of thefollowing components: a processing component 101, a memory 102, a powersupply component 103, a sensor component 107 and a communicationscomponent 108. Not all of the foregoing components are necessary. Theterminal 100 may add other components or delete some components based ona function requirement of the terminal 100. This is not limited in thisembodiment.

The processing component 101 usually controls an overall operation ofthe terminal 100, for example, an operation associated with flightcontrol, data communication, a camera operation and a recordingoperation. The processing component 101 may include one or moreprocessors 109 to execute an instruction to complete all or some stepsof the foregoing operation. In addition, the processing component 101may include one or more modules, for convenience of interaction betweenthe processing component 101 and another component.

The memory 102 is configured to store various types of data to supportan operation of the terminal 100. An example of the data includes aninstruction that is of any application program or method and that isused for being operated on the terminal 100. The memory 102 may beimplemented by using a volatile or non-volatile storage device of anytype or a combination of volatile and non-volatile storage devices, forexample, a static random access memory (SRAM), an electrically erasableprogrammable read-only memory (EEPROM), an erasable programmableread-only memory (EPROM), a programmable read-only memory (PROM), aread-only memory (ROM), a magnetic memory, a flash memory, a magneticdisk or an optical disc. The memory 102 further stores one or moremodules. The one or more modules are configured to be executed by theone or more processors 109 to complete all or some steps in any of themethods shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4.

The power supply component 103 supplies power to various components ofthe terminal 100. The power supply component 103 may include a powersupply management system, one or more power supplies and othercomponents associated with power generation, management and distributionof the terminal 100.

The sensor component 107 includes one or more sensors, configured toprovide state evaluation of each aspect for the terminal 100. Forexample, the sensor component 107 may detect an on/off state of theterminal 100 and a relative position of the component. The sensorcomponent 107 may further detect a position change of the terminal 100or a component of the terminal 100 and a luminance change of theterminal 100. In some embodiments, the sensor component 107 may furtherinclude a magnetic sensor, a pressure sensor or a light sensor.

The communications component 108 is configured for convenience of wiredor wireless communication between the terminal 100 and another device.The terminal 100 may access a communications standard-based wirelessnetwork such as Wireless Fidelity (WiFi), 2G, 3G, or a combinationthereof. In an exemplary embodiment, the communications component 108receives a broadcast signal or broadcast-related information from anexternal broadcast management system by using a broadcast channel. In anexemplary embodiment, the communications component 108 further includesa Near Field Communication (NFC) module for facilitating short-rangecommunication. For example, the NFC module may be implemented based on aradio frequency identification (RFID) technology, an Infrared DataAssociation (IrDA) technology, an ultra-wideband (UWB) technology, aBluetooth (BT) technology and another technology.

In an exemplary embodiment, the terminal 100 may be implemented by oneor more application-specific integrated circuits (ASIC), digital signalprocessors (DSP), programmable logic devices (PLD), field-programmablegate arrays (FPGA), controllers, microcontrollers, microprocessors orother electronic elements, to perform the foregoing method.

A specific manner of performing an operation by the processor of theterminal in this embodiment is described in detail in the embodimentsrelated to the aircraft control method, which is not described in detailherein again.

Optionally, the present invention further provides an aircraft toperform all or some steps of any of the aircraft control methods shownin FIG. 1, FIG. 2, FIG. 3 and FIG. 4. The aircraft includes:

at least one processor; and

a memory in communication connection with the at least one processor,where

the memory stores an instruction executable by the at least oneprocessor and the instruction is executed by the at least one processor,so that the at least one processor is enabled to perform the aircraftcontrol method according to any of the foregoing exemplary embodiments.

In an exemplary embodiment, a storage medium is further provided. Thestorage medium is a computer-readable storage medium. For example, thestorage medium may be a transitory or non-transitory computer-readablestorage medium including an instruction. The storage medium may be, forexample, a memory 102 including an instruction. The instruction may beexecuted by the processor 109 of the terminal 100 to complete theforegoing aircraft control method.

FIGS. 9-10 disclose an aircraft to implement the above method. Theaircraft includes a main body 1, a battery 9 accommodated in the mainbody 1. The aircraft also includes a plurality of arms 2, where each arm2 is connected to the main body 1. A propulsion assembly is disposed oneach arm 2, where the propulsion assembly includes a motor 3 and apropeller 4. The motor 3 is installed on a distal end of the arm 2, andthe propeller 4 is fixedly connected to the shaft of the motor 3 so thatthe motor 3 drives the propeller 4 to rotate in clockwise orcounterclockwise direction.

The aircraft also includes a forward camera 5 installed at the front ofthe main body 1. The camera 5 is configured to capture an image of anarea in front of the aircraft. In an embodiment of the invention, thecamera 5 is a binocular camera which includes two cameras. In anotherembodiment, the camera 5 is a monocular camera.

The aircraft includes a gimbal camera 6, where the camera 6 is connectedto the bottom (lower member) of the main body 1. The gimbal camera 6 isconfigured to capture an image of an object in which a user isinterested. Alternatively, the gimbal camera 6 is remotely controlled bya remote controller.

In an embodiment, the aircraft includes a landing gear 7. The landinggear can be connected to a lower portion of the main body 1 or a lowerportion of the arm 2. For example, as shown in FIG. 9, the gear 7 isconnected to the lower portion of the distal end of the arm 2 andinstalled under the motor 3. The aircraft includes at least two gears 7.In some embodiments, some or all of the gears 7 are foldable.

An indicator 8 is installed on the aircraft. In an embodiment, theindicator 8 is installed on a distal end of the arm 2, as shown in FIG.9. In another embodiment, the indicator can be installed on the gear 7or on the main body 1. The indicator can be a LED lamp.

A downward camera 10 is disposed at bottom of the main body 1. Thecamera 10 is configured to capture an image of an area under of theaircraft. In an embodiment, the camera 10 is a binocular camera whichincludes two cameras. In another embodiment, the camera 10 is amonocular camera.

Furthermore, the aircraft includes a light emitting apparatus 11. In anembodiment, the light emitting apparatus 11 is disposed at a lowerportion or an upper portion of the main body 1. For example, as shown inFIG. 10, the light emitting apparatus 11 is disposed on the lowerportion of the main body 1. In another embodiment, the light emittingapparatus 11 is disposed on the front side or rear side of the main body1. In some other embodiments, the light emitting apparatus 11 isdisposed on the arm 2. The number of the light emitting apparatus is notlimited in the invention. The aircraft can includes one or more lightemitting apparatus. For example, as shown in FIG. 10, the aircraftincludes two light emitting apparatuses 11. In an embodiment, the lightemitting apparatus 11 includes at least one of a signal indicator, a LEDlamp, and an incandescent lamp.

In an embodiment, a vision system is provided on the aircraft. Thevision system includes a processor and at least one camera, wherein theprocessor is disposed within the main body 1 and the camera of thevision system is disposed on the main body 1 or on the arm 2. Forexample, the aircraft includes a forward vision system, a backwardvision system, and a downward vision system. The forward vision systemincludes a process and the camera 5. The backward vision system includesa processor and a camera which is installed at the rear end of the mainbody 1. The downward vision system includes a processor and the camera10. Optionally, the aircraft includes a vision system comprising aprocessor and the gimbal camera 6. The processor of the vision system isconfigured to, perform the step S110 of the method discussed above.

Furthermore, the aircraft includes a flight control system (not shown inthe Figures). The flight control system is disposed within the main body1. The flight control system is configured to control the flight of theaircraft. The flight control system can be implemented as an ASIC or aFPGA.

In an embodiment, the flight control system is configured to perform thesteps S310, S120 and S130 of the method as discussed above. In anotherembodiment, the steps S310, S120 and S130 of the above method areperformed by the processor of the vision system. In some otherembodiments, some of the steps S310, S120 and S130 are performed by theflight control system and the remaining step(s) is (are) performed bythe processor of the vision system.

It should be understood that the present invention is not limited to theprecise structures described above and shown in the accompanyingdrawings and various modifications and changes can be made by a personskilled in the art without departing from the scope of the presentinvention. The scope of the present invention is limited only by theappended claims.

What is claimed is:
 1. A method of controlling an aircraft, comprising:obtaining ambient luminance data, wherein the ambient luminance dataindicates ambient luminance of an environment, wherein the aircraft islocated in the environment; determining a flight height of the aircraft;determining whether the flight height is less than a preset low-altitudeheight threshold; determining whether the ambient luminance datasatisfies a luminance value required for normal running of a visionsystem of the aircraft; and based on a determination that the flightheight is less than the preset low-altitude height threshold and thatthe ambient luminance data fails to satisfy the luminance value,adjusting a working status of a light emitting apparatus on theaircraft.
 2. The method according to claim 1, wherein the obtaining theambient luminance data comprises: obtaining, by the vision system, theambient luminance data, wherein the ambient luminance data comprises anexposure amount.
 3. The method according to claim 2, wherein thedetermining whether the ambient luminance data satisfies the luminancevalue required for normal running of the vision system comprises:determining whether a value of the exposure amount is less than a presetexposure threshold; and based on a determination that the value of theexposure amount is less than the preset exposure threshold, determiningthat the ambient luminance data does not satisfy the luminance valuerequired for normal running of the vision system of the aircraft.
 4. Themethod according to claim 2, wherein the adjusting the working status ofthe light emitting apparatus on the aircraft comprises: adjusting lightemitting luminance of the light emitting apparatus based on the exposureamount, wherein the exposure amount is negatively correlated to thelight emitting luminance.
 5. The method according to claim 1, whereinthe obtaining the ambient luminance data comprises: obtaining, by thevision system, the ambient luminance data, wherein the ambient luminancedata comprises optical flow equality.
 6. The method according to claim5, wherein the determining whether the ambient luminance data satisfiesthe luminance value required for normal running of the vision system ofthe aircraft comprises: determining whether a value of the optical flowquality is less than a preset optical flow quality threshold; and based,at least in part, on a determination that the value of the optical flowquality is less than the optical flow quality threshold, determiningthat the ambient luminance data does not satisfy the luminance valuerequired for normal running of the vision system of the aircraft.
 7. Themethod according to claim 5, wherein the adjusting the working status ofthe light emitting apparatus on the aircraft comprises: adjusting lightemitting luminance of the light emitting apparatus based on the opticalflow quality, wherein the optical flow quality is negatively correlatedto the light emitting luminance.
 8. The method according to claim 1,wherein the obtaining the ambient luminance data comprises: detecting aframe rate of an optical flow image;
 9. The method according to claim 8,wherein the determining whether the ambient luminance data satisfies theluminance value required for normal running of the vision system of theaircraft comprises: determining whether the frame rate of the opticalflow image is less than a preset frame rate threshold; based on adetermination that the frame rate of the optical flow image is less thanthe preset frame rate threshold, determining that the ambient luminancedata does not satisfy the luminance value required for normal running ofthe vision system of the aircraft.
 10. The method according to claim 1,wherein the aircraft comprises a plurality of the light emittingapparatuses.
 11. The method according to claim 10, wherein the adjustingthe working status of the light emitting apparatus on the aircraftcomprises: adjusting the working status of the light emitting apparatusthat is related to the vision system of the aircraft.
 12. The methodaccording to claim 1, wherein the adjusting the working status of thelight emitting apparatus on the aircraft comprises: controlling on oroff of the light emitting apparatus.
 13. The method according to claim1, wherein the adjusting the working status of the light emittingapparatus on the aircraft comprises: adjusting light emitting luminanceof the light emitting apparatus; or changing a light color of the lightemitting apparatus.
 14. The method according to claim 1, wherein if theflight height is greater than the preset low-altitude height threshold,the method further comprises: turning off the light emitting apparatus.15. The method according to claim 1, wherein the light emittingapparatus comprises at least one of a signal indicator, a lightingemitting diode (LED) lamp, and an incandescent lamp.
 16. The methodaccording to claim 1, wherein the vision system comprises at least oneof a monocular camera, a binocular camera, and a gimbal camera.
 17. Anaircraft, comprising: a memory storing an executable instruction; and aprocessor in communication connection with the memory; wherein when theexecutable instruction is implemented by the processor, the processor isconfigured to: obtain ambient luminance data, wherein the ambientluminance data indicates ambient luminance of an environment, whereinthe aircraft is located in the environment; determine a flight height ofthe aircraft; determine whether the flight height is less than a presetlow-altitude height threshold; determine whether the ambient luminancedata satisfies a luminance value required for normal running of a visionsystem of the aircraft; and based on a determination that the flightheight is less than the preset low-altitude height threshold and thatthe ambient luminance data fails to satisfy the luminance value, adjusta working status of a light emitting apparatus on the aircraft.
 18. Theaircraft according to claim 17, wherein the ambient luminance datacomprises an exposure amount, and the processor is configured to:determine whether a value of the exposure amount is less than a presetexposure threshold; and based on a determination that the value of theexposure amount is less than the preset exposure threshold, determinethat the ambient luminance data does not satisfy the luminance valuerequired for normal running of the vision system of the aircraft. 19.The aircraft according to claim 18, wherein the processor is configuredto adjust light emitting luminance of the light emitting apparatus basedon the exposure amount, wherein the exposure amount is negativelycorrelated to the light emitting luminance.
 20. The aircraft accordingto claim 17, wherein the ambient luminance data comprises optical flowequality, and the processor is configured to: determine whether a valueof the optical flow quality is less than a preset optical flow qualitythreshold; and based, at least in part, on a determination that thevalue of the optical flow quality is less than the optical flow qualitythreshold, determine that the ambient luminance data does not satisfythe luminance value required for normal running of the vision system ofthe aircraft.
 21. The aircraft according to claim 20, wherein theprocessor is configured to adjust light emitting luminance of the lightemitting apparatus based on the optical flow quality, wherein theoptical flow quality is negatively correlated to the light emittingluminance.
 22. The aircraft according to claim 17, wherein the processoris configured to: control on or off of the light emitting apparatus; oradjust luminance of the light emitting apparatus;
 23. The aircraftaccording to claim 17, wherein the processor is configured to turn offthe light emitting apparatus if the flight height is greater than thepreset low-altitude height threshold.
 24. An aircraft, comprising: amain body; an arm connected to the main body; a propulsion assemblydisposed on the arm, wherein the propulsion assembly comprises a motorand a propeller; a vision system disposed on the main body, wherein thevision system comprises a camera and a processor; a flight controlsystem disposed in the main body; and a light emitting apparatusdisposed on the main body or on the arm; wherein the processor of thevision system is configured to obtain ambient luminance data through thecamera of the vision system, wherein the ambient luminance dataindicates ambient luminance of an environment, the aircraft beinglocated in the environment; wherein one of the flight control system andthe processor of the vision system is configured to: determine a flightheight of the aircraft; determine whether the flight height is less thana preset low-altitude height threshold; determine whether the ambientluminance data satisfies a luminance value required for normal runningof the vision system; and based on a determination that the flightheight is less than the preset low-altitude height threshold and thatthe ambient luminance data fails to satisfy the luminance value, adjusta working status of the light emitting apparatus.
 25. The aircraftaccording to claim 24, wherein the ambient luminance data comprises anexposure amount; wherein the one of the flight control system and theprocessor of the vision system is configured to: determine whether avalue of the exposure amount is less than a preset exposure threshold;and based on a determination that the value of the exposure amount isless than the preset exposure threshold, determine that the ambientluminance data does not satisfy the luminance value required for normalrunning of the vision system.
 26. The aircraft according to claim 25,wherein the one of the flight control system and the processor of thevision system is configured to adjust light emitting luminance of thelight emitting apparatus based on the exposure amount, wherein theexposure amount is negatively correlated to the light emittingluminance.
 27. The aircraft according to claim 24, wherein the aircraftcomprises a plurality of the light emitting apparatuses.
 28. Theaircraft according to claim 24, wherein the one of the flight controlsystem and the processor of the vision system is configured to: controlon or off of the light emitting apparatus; or adjust luminance of thelight emitting apparatus; or change a light color of the light emittingapparatus.
 29. The aircraft according to claim 24, wherein the one ofthe flight control system and the processor of the vision system isconfigured to turn off the light emitting apparatus if the flight heightis greater than the preset low-altitude height threshold.
 30. Theaircraft according to claim 24, wherein the light emitting apparatuscomprises at least one of a signal indicator, a lighting emitting diode(LED) lamp, and an incandescent lamp; wherein the camera of the visionsystem comprises at least one of a monocular camera, a binocular camera,and a gimbal camera.